Feed for web press



Feb. 3, 1959 E. E. HARKINS ET AL FEED FOR WEB PRESS Filed Dec. 15, 1956 INVENTOR. fun fuel: Hun/v.5 001v H. Ka /v6 M MW United States Patent 0.

FEED For; WEB PRESS Elza Eugene Harkius and Don H. Young, Athens, Ohio, assignors to Royal McBee Corporation, New York, N. Y., a corporation of New York Application December 13, 1956, Serial No. 628,064

1 Claim. (Cl. 2712.2)

This invention relates to printing presses for printing on an intermittently advancing continuous web and a web feeder therefor.

Printing presses designed for use in printing on a continuous web of material require that the web be intermittently advanced in the press by indexing rolls so that the web is advanced into printing position, the web being then stopped for the printing step. After the web has been printed, a fresh part of the web is then advanced into the printing position so that it too, in turn, is printed. Tension control means are employed as the web enters the press, so that the indexing rolls may pull on the web against a substantially constant tension in order that accurate registration of the web is obtained in the printing station of the press. If the tension on the web varies as it is pulled by the indexing rolls, then accurate registration of the printing is difficult.

Normally, the web to be worked upon by the printing press is stored in the form of a large heavy mill roll, the web being unwound from the mill roll to pass into the press. It is necessary that the mill roll be unwound in such a manner as to leave a slack feed loop in the web for the press, as it is not possible for the indexing rolls of the press to directly pull the web from the mill roll in intermittent steps, as the inertia of the mill roll at rest would merely cause the web to break if it were attempted to suddenly pull a portion of the web from the roll.

One manner in which a web feed has been used with a continuous web press is to mount the mill roll on a mill roll stand with a manually adjustable brake to prevent free rotation of the roll on the stand. Continuously driven pull rolls are then applied to the web to unwind the web from the mill roll and to form a slack loop on the floor on which the mill stand and press are mounted. The web was then directed back over the mill roll and directly to the tension control blocks of the press. The unwind speed of the mill roll was regulated so that a multiple feed loop was formed in the length of the web on the floor, so that there would be suflicient slack in the web to meet the demands of the indexing rolls of the press without pulling the web directly from the mill roll.

This system has the disadvantage that the indexing rolls must pull the weight of the web which extended from the tension control blocks around the mill roll to the slack loop which lay on the floor. In addition, a considerable friction drag of the web over the mill roll resulted. This load on the indexing rolls as a result of the web weight and friction was variable and uncontrollable with a consequent loss of registration control in the press.

Furthermore, the manually adjustable brake on the mill stand was a contributing factor to the loss of registration control because of a constantly increasing unwind tension on the web as the mill roll diameter decreased.

Therefore, it is an object of this invention to provide an intermitently advancing continuous web press with a "ice web feed means having a mill roll with means to continually unwind the roll and means to form a slack feed loop in the web in close adjacency of the tension control blocks of the press to eliminate the load variation on the indexing rolls of the press.

It is a further object of this invention to provide a web feeder for a printing press having indexing rolls and web tension control blocks, in which the web feeder comprises a mill roll, means to continually unwind the web from the mill roll, and means to pull the unwound web tautly around the mill roll to form a slack loop in immediate advance of the tension control 'blocks of the press.

Other objects and advantages will be seen in the course of the following description.

In the accompanying drawings, forming a part of this specification, the figure illustrates a schematic representation of an embodiment of this invention.

In the drawing, wherein for purposes of illustration is shown a preferred embodiment of the invention, a mill roll 1, having a supply of webbing 2 thereon, is mounted for rotation on a horizontally disposed axle 3. The webbing is trained around dancer or idler rolls 4, 5, 6 and 7, to pass between the unwind rolls 8 and 9 which are driven by a conventional drive means (not shown) to provide an automatic and constant tension control on the web 2 as it is pulled from the mill roll.

The web 2 is then directed to pass from the unwinding rolls around a portion of the periphery of the mill roll 1 to a pull roll 10 situated above the mill roll and on the same side of the mill roll as are the unwind rolls 8 and 9. A power drive means 11 provides a continuous drive to the pull roll 10 through endless belt 12 to pull the web taut from the unwind rolls 8 and 9 around the mill 'roll 1. An adjustable pressure roller 13 enables the pull roll 10 to frictionally act on the web 2 to pull the web therethrough.

The pull roll 10 is situated in relative close adjacency to the tension control blocks 14 of the press so that a slack feed loop 15 is formed in the web in immediate advance of the tension control blocks 14. The web is continuously gripped between the tension control blocks 14. After the web passes through the tension control blocks 14, it is continuously gripped by the intermittently operating indexing rolls l6 and 17 of the press.

As is thus seen, the slack feed loop 15 of the web is formed in close adjacency to the tension control blocks 14 to greatly eliminate any variable load factors arising as a result of the slack feed loop being formed at a position remote from the tension control blocks. By the present arrangement, the load imposed upon the indexing rolls is substantially that brought about by the fixed tension control blocks, and the registration accuracy of the press is greatly enhanced.

It is to be understood that the form of the invention, herewith shown and described, is to be taken as a preferred embodiment of the same, and that various changes in the size. shape and arrangement of parts may be resorted to, without departing from the spirit of our invention, or the scope of the attached claim.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

In combination, a printing press having a pair of intermittently operating indexing feed rolls for continuously gripping and intermittently advancing a continuous web therebetween to printing position, a pair of tension control blocks for continuously engaging said web therebetween to provide a constant tension in said web between said indexing feed rolls and said tension control blocks as said web is advanced during operation of said indexing feed rolls, a rotatable mill roll having a supply v 2,879,188 3 4 n of webbing wound thereon, unwind roll means for unfeed loop of said webbing in immediate advance of said winding said webbing from said mill roll at a constant tension control blocks. rate, said unwind roll means being situated below said mill roll, and pull roll means above said mill roll and References Cited in the fil f this patent on the same side thereof as said unwind roll means for 5 continually pulling said webbing from said unwind roll UNITED STATES PATENTS means tautly around said mill roll; said pull roll means being situated above and in relatively close adjacency to 2295960. Staldel' P 1942 said tension control blocks to form a Varying length slack 2,553,834 Rohland May 22, 1951 

